다발성 낭종성 병변을 보인 급성 파종성 뇌척수염 - 증례보고 -

김대원,김태영,김종문,윤기중,Kim, Dae Won,Kim, Tae Young,Kim, Jong Moon,Yun, Ki Jung 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.5

Acute disseminated encephalomyelitis(ADEM) is an uncommon immune-mediated inflammatory demyelinating disorder that typically affects the white matter of the central nervous system. Radiologic findings of acute disseminated encephalomyelitis are not pathognomomic. The differential diagnosis is always difficult. Occasionally, the clinical features, radiological and histopathological findings of patients with acute disseminated encephalomyelitis mimic the brain tumor or other space occupying lesions. The authors report a 6-year-old girl who presented with right hemiparesis two days after nausea and vomiting. Brain MRI of the patient revealed non-enhanced multiple cystic lesions in subcortical white matter of both cerebral hemisphere with prominent edema. One of the cystic lesions was resected to differentiate with metastatic tumor or inflammatory disease such as abscess and confirmed as the acute disseminated encephalomyelitis via various immunohistochemical stains. Pertinent literature is reviewed with discussion on this uncommon ADEM associated with multiple cystic lesions.

제 1 형 신경섬유종증과 동반된 교육종

김대원,박종태,김종문,김태영,Kim, Dae Won,Park, Jong Tae,Kim, Jong Moon,Kim, Tae Young 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.2

A rare case of gliosarcoma with neurofibromatosis type I is presented. The patient was a 33-year-old woman who had headache and vomiting for one week. Multiple neurofibromas over her whole body with many cafeau- lait spots were present since childhood. At admission, she had no focal neurological deficit and ophthalmologic examination revealed bilateral Lisch nodules. Brain CT and MRI revealed a heterogeneously enhancing mass in the left fronto-parietal region with marked peritumoral edema and mass effect. The tumor was removed gross totally and a gliosarcoma was diagnosed histopathologically. Post operative course was uneventful with resolution of symptom, followed by radiotherapy with 60 Gy. A brief overview is given of this rare case together with the pertinent literature.

사람 교모세포종 A172 세포에서 Cisplatin에 의한 세포고사의 유도

김대원,김태영,박종태,김종문,Kim, Dae Won,Kim, Tae Young,Park, Jong Tae,Kim, Jong Moon 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.1

This study was designed to investigate the mechanism of cell death after cisplatin treatment in human glioblastoma A172 cells. Cis-diamminedichloroplatinum(Cisplatin) demonstrated cytostatic or cytotoxic effects on A172 cells in a dosedependent manner. Cisplatin-mediated cytotoxity in A172 cells was revealed as an apoptosis characterized by high molecular weight DNA fragmentation by agarose electrophoresis as well as nuclear fragmentation by Hoechst staining. Cisplatin also resulted in the activation of caspase 3-like protease as well as poly(ADP-ribose) polymerase(PARP) cleavage. Interestingly, the anti-apoptotic Bcl2 protein was degraded and furthermore, expression of p53 protein was increased by cisplatin in a time-dependent manner. Taken together, these results suggest that anticancer drug, cisplatin induces the apoptotic death of human glioblastoma A172 cells via the activations of caspase 3-like protease, degradation of anti-apoptotic Bcl2 protein and increase in the expression of p53.

그린 데이터센터를 위한 전력 관리 기술

김대원,김선욱,김성운,Kim, D.W.,Kim, S.W.,Kim, S.W. 한국전자통신연구원 2009 전자통신동향분석 Vol.24 No.4

언제부터인가 주위는 모두 "녹색" 물결로 뒤덥혀 버렸다. 그 중에서도 IT의 존재는 녹색 물결에 휩싸여 새로운 판로를 모색하고 있다. 데이터센터 역시 그 문제점은 수 년전부터 대두되어 왔고, 정책적으로 혹은 업계 자체적으로 데이터센터의 문제점을 해결하고자 많은 솔루션을 내고 있는 실정이다. 그린 데이터센터를 위한 견해는 먼저 비 IT영역으로 공조, 항온/항습 시설, 전력 배전 시설 등의 관점에서 접근하는 견해가 있고 IT영역으로 서버 자체에 대한 관점에서 접근하는 견해가 있다. 본 고에서는 데이터센터 내에서 IT 영역에 대한 전력 관리를 위하여 해야 될 역할에 대하여 언급하고자 한다. 특히 데이터센터 내 서버 자체의 전력 절감을 위한 방법에 대하여 논하고, 앞선 업체들 특히 IBM, Google, SUN 등의 동향으로부터 그린 데이터센터를 위한 방향을 모색해 보기로 한다.

폐영구자석 황산침출과 분별결정법에 의한 희토류 분리·회수에 대한 연구

김대원,김희선,김보람,진연호,Kim, Dae-Weon,Kim, Hee-Seon,Kim, Boram,Jin, Yun-Ho 한국청정기술학회 2022 청정기술 Vol.28 No.2

Nd-Fe-B waste permanent magnet contains about 20~30% rare earth elements and about 60~70% iron elements, and the rare earth and iron components were recovered through sulfuric acid leaching and fractional crystallization. Oxidation roasting was not performed for separation and recover of the rare earth and iron elements. The leaching characteristics were confirmed by using as variables the sulfuric acid concentration and the mineral solution concentration ratio. Sulfuric acid leaching was carried out for 3 hours for each sulfuric acid concentration. The leached solid phase was characterized for its crystalline phase, composition, and quantitative components by XRD and XRF analysis, and the filtrate was analyzed for components by ICP analysis. With sulfuric acid leaching at 3M sulfuric acid concentration, neodymium compounds were formed, the iron content was the least, and the recovery rate was high. After the filtrate remaining after sulfuric acid leaching was subjected to fractional crystallization through evaporation and concentration, the neodymium component was found to be concentrated 7.0 times and the iron component 2.8 times. In this study, the recovery rate of waste permanent magnets through sulfuric acid leaching and a fractional crystallization method without an oxidation and roasting process was confirmed to be about 99.4%.

업계 시스템 관리 툴 기술 동향 분석

김대원,김선욱,오수철,김성운,Kim, Dae-Won,Kim, Seon-Uk,O, Su-Cheol,Kim, Seong-Un 한국전자통신연구원 2008 전자통신동향분석 Vol.23 No.1

시스템 관리(system management)라 함은 일반적으로 분산 컴퓨터 환경에서의 전사적 시스템 관리를 말한다. 그리고 네트워크가 발전함에 따라서 그 영향력도 매우 커지게 되었고 그 범위 역시 광범위하게 되어 현재 시스템 관리 영역은 하드웨어 및 소프트웨어가 접목된 복잡한 시스템으로 변모해가고 있는 한편 또 이런 복잡함을 줄이기 위하여 각 표준 단체들이 많은 노력을 기울이고 있으며 이에 참여하는 업체들도 점점 늘어나고 있는 추세이다. 본 기고문에서는 클러스터 컴퓨팅 시스템 환경에서 시스템 관리를 위한 목적으로 사용되는 많은 소프트웨어 가운데, 하드웨어 모니터링 및 시스템의 lifecycle 관리에 관한 툴을 위주로 주요 업체들의 기술과 소프트웨어의 개발 동향에 대하여 기술하고자 한다.

공동주택 연도별 단열기준 강화에 따른 에너지소요량 비교 연구

김대원,정광섭,김영일,김성민,Kim, Dae-Won,Chung, Kwang-Seop,Kim, Young-Il,Kim, Sung-Min 한국에너지학회 2013 에너지공학 Vol.22 No.2

에너지사용은 우리생활과 밀접한 관계성을 유지하고 있다. 사계절이 뚜렷한 우리나라로서는 건물분야에 냉,난방이 필수품처럼 여겨지는 세대에 살고있어 에너지 사용과 유지에 새로운 트렌드를 요구하고 있다. 이에따라 정부는 신축 및 기존건축물의 에너지효율 개선을 위해서 단열기준을 지속적으로 강화하여 에너지절감을 꾀하고 있다. 공동주택의 에너지효율 분석중 가장 중요한 요소가 열관류율이며 그값은 외피면적비에 대한 창면적비에 따라 난방에너지 요구량이 큰차이를 보여주고 있다. 그러므로 지속적인 효율개선 정책과 외피면적에 대한 창면적비의 규제가 필요한 시점이라 생각한다. Energy consumption is closely related to our lives. As Korea has four seasons, heating and cooling system is considered as essential facilities for the residential buildings. Accordingly, the government has continuously strengthened the design criteria to improve energy for new and existing building to save energy. The most important factor in the energy efficiency analysis for apartment is the heat transmission coefficient, and the value is significantly different as the heating energy amount is greatly different according to the window area ratio versus facade area ratio. Therefore, it is time to conduct continuous set-up for goal to enhance efficiency and restriction on window area ratio versus facade area ratio.

스퍼터링 타겟용 Cu-50In-13Ga 3원계 합금 분말의 소결 및 압연 거동

김대원,김용호,김정한,김대근,이종현,최광보,손현택,Kim, Dae-Won,Kim, Yong-Ho,Kim, Jung-Han,Kim, Dae-Guen,Lee, Jong-Hyeon,Choi, Kwang-Bo,Son, Hyeon-Taek 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.4

In this study, we mainly focus on the study of densification of gas-atomized Cu-50 wt.%In-13 wt.%Ga alloy powder without occurrence of crack during the forming process. Cu-50 wt.%In-13 wt.%Ga alloy powder was consolidated by sintering and rolling processes in order to obtain high density. The phase and microstructure of formed materials were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM), respectively. Warm rolling using copper can result in the improvement of density. The specimen obtained with 80% of rolling reduction ratio at $140^{\circ}C$ using cooper can have the highest density of $8.039g/cm^3$.

Traffic Analysis of a CAN-based Control System

김대원,Kim, Dae-Won Institute of Korean Electrical and Electronics Eng 2001 전기전자학회논문지 Vol.5 No.1

This paper deals with an architecture of network-based control system using the CAN(Controller Area Network) protocol and its traffic analysis. It is difficult to determine an optimal network-based control architecture for a specific AGV(Autonomous Guided Vehicle) system with a manipulator arm. The fixed number of periodic messages to be occurred is pre-defined in the system. To determine whether the proposed system architecture is effective or not, we perform traffic analysis for the real-time communication of all messages. Through simulations, the range of transmission speed is found satisfying required conditions and the permissible number of additional sensors is investigated for improving the system performance, when the sampling periods of analog sensors are determined under fixed condition that the transmission speed is over 500Kbps.

NaLa(SO₄)₂·H₂O 결정상으로부터 이온치환반응에 의한 산화란탄 (La₂O₃) 분말 합성에 관한 연구

김대원,안낙균,심현우,이찬기,최희락,홍현선,Kim, Dae-Weon,Ahn, Nak-Kyoon,Shim, Hyun-Woo,Lee, Chan-Gi,Choi, Hee-Lack,Hong, Hyun Seon 한국결정성장학회 2018 韓國結晶成長學會誌 Vol.28 No.5

The recovery of rare earth elements (REE) including La, Nd and Ce from spent batteries is important issues to reuse scarce resources. Herein, we present a simple recovery process to obtain lanthanum oxide ($La_2O_3$) from spent Ni-MH batteries, and demonstrate the conversion mechanism from $NaLa(SO_4)_2{\cdot}H_2O$ to $La_2O_3$. This strategy requires the initial preparation of $NaLa(SO_4)_2{\cdot}H_2O$ and subsequent metathesis reaction with $Na_2CO_3$ at $70^{\circ}C$. This metathesis reaction resulted in the crystalline lanthanum carbonate hydrate ($La_2(CO_3)_3{\cdot}xH_2O$) powder with plate-like morphology. On the basis of TGA result, the $La_2(CO_3)_3{\cdot}xH_2O$ powder was calcined in air at three different temperatures, that is, $300^{\circ}C$, $500^{\circ}C$, and $1000^{\circ}C$. As the calcination temperature increased, the morphology of powder was changed; prism-like ($NaLa(SO_4)_2{\cdot}H_2O$) ${\rightarrow}$ platelike ($La_2(CO_3)_3{\cdot}xH_2O$) ${\rightarrow}$ aggregated irregular shape ($La_2O_3$). Futhermore, XRD results indicated that the crystalline $La_2O_3$ could be synthesized after the metathesis reaction with $Na_2CO_3$, followed by heat-treatment at $1000^{\circ}C$, along with a change of crystallographic structures; $NaLa(SO_4)_2{\cdot}H_2O$ ${\rightarrow}$ $La_2(CO_3)_3{\cdot}xH_2O$ ${\rightarrow}$ $La_2O_3$. 폐니켈수소전지에 함유된 희토류들의 회수는 자원 재활용을 위한 중요한 이슈 중의 하나이다. 본 논문에서는 폐니켈수소전지에 함유된 주요 희토류 성분 중의 하나인 란탄의 회수와 산화물로 전환되는 메커니즘 연구를 위하여, 재활용 공정에서 확보되는 희토류 침전물($NaRE(SO_4)_2{\cdot}H_2O$, RE = La, Nd, Ce)과 같은 단일 조성의 $NaLa(SO_4)_2{\cdot}H_2O$ 분말을 합성하였다. 합성된 분말은 $70^{\circ}C$에서 진행된 탄산나트륨과의 이온치환반응을 통해 판상형의 $La_2(CO_3)_3{\cdot}xH_2O$ 결정상을 나타냈으며, 비교를 위해 상온에서 진행된 치환 반응을 진행하였다. 이후 산화란탄 합성을 위해 TG 분석 결과를 바탕으로, $La_2(CO_3)_3{\cdot}xH_2O$ 분말을 $300^{\circ}C$, $500^{\circ}C$ 및 $1000^{\circ}C$에서 후열처리를 진행하였으며, 이에 따른 결정구조의 변화를 분석하였다. FESEM 결과 본 연구에서 합성된 각각의 분말들은 각기둥($NaLa(SO_4)_2{\cdot}H_2O$), 판상($La_2(CO_3)_3{\cdot}xH_2O$) 및 특정 형상 없이 불규칙적으로 응집된 형태($La_2O_3$)를 나타내었다.